Signaling method for a pen driver circuit interface

Abstract

A signaling method for a pen driver circuit interface is embodied in a signal interface between a controller circuit and a pen driver circuit for a printer. At least one signal of the interface is omitted; and the pen driver circuit is modified to process a combination of signals including at least one of the signals on the signal interface to provide information pertaining to the at least one omitted signal. According to a preferred method, the combination of signals are processed when data is not being transferred via the signal interface to provide a pen firing control signal for the printer such as a warm enable signal or a fire enable signal.

I claim:  
     
       1. A signaling method comprising: 
       providing a signal interface between a controller circuit and a printer pen driver circuit; and  
       deriving a warm enable pulse signal from a combination of signals, the combination of signals including at least one data transfer signal provided to the pen driver circuit by the signal interface.  
     
     
       2. A signaling method according to  claim 1 , wherein the at least one data transfer signal includes a load signal. 
     
     
       3. A signaling method according to  claim 1 , wherein the at least one data transfer signal includes a clock signal.